A Problematic Map of Stop-and-Frisk

One of the biggest stories in America's biggest city this year has been the public debate about the NYPD's "stop-and-frisk" tactic. The general idea is that officers can stop someone if there's a reasonable suspicion the person will commit a crime, and can frisk the person if they suspect the presence of a weapon. City authorities say stop-and-frisk reduces illegal guns and crime. Opponents say it intrudes on civil liberties and leads to racial profiling.

A central point in the debate is the startling disparity between the high number of stop-and-frisk incidents that occur and the low number of illegal guns that are recovered. But this point can be interpreted two ways. Police officials say it proves the system is working (i.e. stop-and-frisks have deterred people from carrying weapons), while civil liberties advocates say it proves the system isn't (i.e. stop-and-frisks are excessive and ineffectual).